1. Field of the Invention
The invention relates to float switches and more specifically, the invention relates to float switches which open and close an electrical circuit in response to the repositioning of a sphere within a raceway caused by a change in the attitude of the switch, and a seal/strain relief fastener.
2. Discussion of the Prior Art
Many different types of float switches have been developed for opening and closing an electrical circuit in response to the level of a liquid within a reservoir. Generically, float switches include a floating buoy and a means, responsive to the vertical position of the bouy, for alternately closing an electrical circuit when the float achieves a predetermined maximum height and opening the electrical circuit when the float achieves a predefined minimum height, normally open, or normally closed.
One type of available float switch is known as a sphere-actuated float switch as taught by U.S. Pat. No. 5,142,108 to Johnston et al, which includes a cage defining a longitudinal raceway, a yoke pivotally mounted externally to the stage and having first and second legs which extend into the raceway, an electrical switching means which is electrically open when the yoke is in a first position and electrically closed when the yoke is in a second position, an over-center spring capable of biasing the yoke into the apropriate electrically closed positions once the yoke is urged past a transition point, and a sphere within the raceway for urging the yoke between the electrically open and the electrically closed positions.
Another type of available float switches is known as a mercury-actuated switch. Mercury-actuated float switches provide superior switching performance, however, because of environmental concerns relating to the use of mercury, alternatives to the mercury-actuated switch are being explored.